Cialis in Bodybuilding?

Im sure that title caught your eye and many are probably thinking “I don’t have ED so why would anyone take cialis for bodybuilding?” Well, surprisingly enough, cialis or tadalafil, holds some merit when it comes to improving physique development. Tadalafil is a PDE-5 (phosphodiesterase type 5 enzyme) inhibitor that enters the bloodstream and prevents the breakdown of cGMP (this is how it works as a potent ED medication.) Tadalafil’s pharmacodynamics in particular extend beyond its ability to be a potent nitric oxide aid as it also possesses tumor fighting properties, aids in the suppression of certain cancerous cells, increase lipid metabolism, increase protein synthesis efficiency, and has the potential to be a potent positive nutrient partitioner given its ability to enhance bloodflow.

Califano et al conducted a study entitled “Tadalafil augments tumor specific immunity in patients with head and neck squamous cell carcinoma.” Their purpose was to determine if phosphodiesterase 5 (PDE5) inhibitors can augment immune function in head and neck cancer patients through inhibition of myeloid derived suppressor cells (MDSCs). They performed a randomized, prospective, double blinded, placebo controlled, phase II clinical trial to determine the in vivo effects of systemic PDE5 inhibition on immune function in head and neck squamous cell carcinoma (HNSCC) patients. The results were that they found that tadalafil augmented immune response, increasing ex vivo T cell expansion to a mean 2.4 fold increase compared to 1.1 fold in control patients (P= 0.01), reducing peripheral MDSC numbers to mean 0.81 fold change compared to a 1.26 fold change in control patients (P=0.001), and increasing general immunity as measured by delayed type hypersensitivity response (P=0.002). Tumor specific immunity in response to HNSCC tumor lysate was augmented in tadalafil treated patients (P=0.04). They concluded by stating “these findings demonstrate that tadalafil augments general and tumor-specific immunity in HNSCC patients and has therapeutic potential in HNSCC. Evasion of immune surveillance and suppression of systemic and tumor specific immunity is a significant feature of head and neck cancer development. This study demonstrates that a PDE5 inhibitor, tadalafil, can reverse tumor specific immune suppression in head and neck cancer patients, with potential for therapeutic application” (1.)

Now I know what you’re all wondering, where is the research for its effects on lipid metabolism and protein synthesis? For that, we begin with looking at work from Valeria De Arcangelis et al that looked at possible pathways in tadalafil amelioration of Duchenne Muscular Dystrophy. They state within the abstract “numerous therapeutic approaches for Duchenne and Becker Muscular Dystrophy (DMD and BMD), the most common X-linked muscle degenerative disease, have been proposed. So far, the only one showing a clear beneficial effect is the use of corticosteroids. Recent evidence indicates an improvement of dystrophic cardiac and skeletal muscles in the presence of sustained cGMP levels secondary to a blocking of their degradation by phosphodiesterase five (PDE5). Due to these data, we performed a study to investigate the effect of the specific PDE5 inhibitor, tadalafil, on dystrophic skeletal muscle function. Chronic pharmacological treatment with tadalafil has been carried out in mdx mice. Behavioral and physiological tests, as well as histological and biochemical analyses, confirmed the efficacy of the therapy. We then performed a microarray-based genomic analysis to assess the pattern of gene expression in muscle samples obtained from the different cohorts of animals treated with tadalafil. This scrutiny allowed us to identify several classes of modulated genes. Our results show that PDE5 inhibition can ameliorate dystrophy by acting at different levels. Tadalafil can lead to increased lipid metabolism; a switch towards slow oxidative fibers driven by the up-regulation of PGC-1α; an increased protein synthesis efficiency; a better actin network organization at Z-disk” (2.) To illustrate my point even further, The University of Texas Medical Branch, Galveston conducted a clinical trial on The Effect of Sildenafil and Tadalafil on Skeletal Muscle and Perceptual Fatigue (linked here: https://clinicaltrials.gov/ct2/show/NCT01661595.) The Investigators hypothesize that upregulation of skeletal muscle NO-cGMP mediated responses through phosphodiesterase (PDE) inhibition by sildenafil or tadalafil causes an acute anabolic response of skeletal muscle protein synthesis. NO is well-known to elicit vasodilation through stimulation of cGMP signaling, and NO-mediated changes in muscle perfusion may influence both skeletal muscle anabolism and perceptual fatigue. To measure skeletal muscle protein synthesis, we will infuse a stable isotope tracer of phenylalanine and measure its incorporation into skeletal muscle proteins following a dose of sildenafil, tadalafil, or placebo. The Investigators will also determine whether differences exist between men and women in response to PDE inhibition. As skeletal muscle NO-cGMP signaling has been implicated in fatigue responses, we will assess the acute effect of sildenafil and tadalafil on fatigue. Fatigue can be manifested both as a performance deficit at a local level (e.g., a reduced ability of skeletal muscle to produce power or force) as well as a subjective experience of lacking physical or mental energy. Accordingly, we will use more than one means (skeletal muscle performance, fatigue questionnaires, accelerometers) to study fatigue. The Investigators hypothesize that sildenafil or tadalafil will acutely reduce exercise-associated fatigability and skeletal muscle fatigue development.

Although this is yet another brief overview of some of the benefits that tadalafil can offer a bodybuilder, it should serve the purpose to get the gears of your mind turning and eager to research more on this topic matter! In terms of practical application, 20mgs taken roughly 30-60 minutes prior to your workout seems to be a very common starting point (although some get tremendous benefits from only 10mgs while others need to go upwards of 40mgs.) Some people find that undulating their dosage from a low to high repeating strategy is most effective for long term usage. As with everything, more does not equal better.